1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Driver for the enhanced rotary controller on pxa930 and pxa935
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/module.h>
  8#include <linux/interrupt.h>
  9#include <linux/input.h>
 10#include <linux/platform_device.h>
 11#include <linux/io.h>
 12#include <linux/slab.h>
 13
 14#include <linux/platform_data/keyboard-pxa930_rotary.h>
 15
 16#define SBCR	(0x04)
 17#define ERCR	(0x0c)
 18
 19#define SBCR_ERSB	(1 << 5)
 20
 21struct pxa930_rotary {
 22	struct input_dev	*input_dev;
 23	void __iomem		*mmio_base;
 24	int			last_ercr;
 25
 26	struct pxa930_rotary_platform_data *pdata;
 27};
 28
 29static void clear_sbcr(struct pxa930_rotary *r)
 30{
 31	uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
 32
 33	__raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
 34	__raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
 35}
 36
 37static irqreturn_t rotary_irq(int irq, void *dev_id)
 38{
 39	struct pxa930_rotary *r = dev_id;
 40	struct pxa930_rotary_platform_data *pdata = r->pdata;
 41	int ercr, delta, key;
 42
 43	ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
 44	clear_sbcr(r);
 45
 46	delta = ercr - r->last_ercr;
 47	if (delta == 0)
 48		return IRQ_HANDLED;
 49
 50	r->last_ercr = ercr;
 51
 52	if (pdata->up_key && pdata->down_key) {
 53		key = (delta > 0) ? pdata->up_key : pdata->down_key;
 54		input_report_key(r->input_dev, key, 1);
 55		input_sync(r->input_dev);
 56		input_report_key(r->input_dev, key, 0);
 57	} else
 58		input_report_rel(r->input_dev, pdata->rel_code, delta);
 59
 60	input_sync(r->input_dev);
 61
 62	return IRQ_HANDLED;
 63}
 64
 65static int pxa930_rotary_open(struct input_dev *dev)
 66{
 67	struct pxa930_rotary *r = input_get_drvdata(dev);
 68
 69	clear_sbcr(r);
 70
 71	return 0;
 72}
 73
 74static void pxa930_rotary_close(struct input_dev *dev)
 75{
 76	struct pxa930_rotary *r = input_get_drvdata(dev);
 77
 78	clear_sbcr(r);
 79}
 80
 81static int pxa930_rotary_probe(struct platform_device *pdev)
 82{
 83	struct pxa930_rotary_platform_data *pdata =
 84			dev_get_platdata(&pdev->dev);
 85	struct pxa930_rotary *r;
 86	struct input_dev *input_dev;
 87	struct resource *res;
 88	int irq;
 89	int err;
 90
 91	irq = platform_get_irq(pdev, 0);
 92	if (irq < 0)
 93		return -ENXIO;
 94
 95	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 96	if (!res) {
 97		dev_err(&pdev->dev, "no I/O memory defined\n");
 98		return -ENXIO;
 99	}
100
101	if (!pdata) {
102		dev_err(&pdev->dev, "no platform data defined\n");
103		return -EINVAL;
104	}
105
106	r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
107	if (!r)
108		return -ENOMEM;
109
110	r->mmio_base = ioremap(res->start, resource_size(res));
111	if (r->mmio_base == NULL) {
112		dev_err(&pdev->dev, "failed to remap IO memory\n");
113		err = -ENXIO;
114		goto failed_free;
115	}
116
117	r->pdata = pdata;
118	platform_set_drvdata(pdev, r);
119
120	/* allocate and register the input device */
121	input_dev = input_allocate_device();
122	if (!input_dev) {
123		dev_err(&pdev->dev, "failed to allocate input device\n");
124		err = -ENOMEM;
125		goto failed_free_io;
126	}
127
128	input_dev->name = pdev->name;
129	input_dev->id.bustype = BUS_HOST;
130	input_dev->open = pxa930_rotary_open;
131	input_dev->close = pxa930_rotary_close;
132	input_dev->dev.parent = &pdev->dev;
133
134	if (pdata->up_key && pdata->down_key) {
135		__set_bit(pdata->up_key, input_dev->keybit);
136		__set_bit(pdata->down_key, input_dev->keybit);
137		__set_bit(EV_KEY, input_dev->evbit);
138	} else {
139		__set_bit(pdata->rel_code, input_dev->relbit);
140		__set_bit(EV_REL, input_dev->evbit);
141	}
142
143	r->input_dev = input_dev;
144	input_set_drvdata(input_dev, r);
145
146	err = request_irq(irq, rotary_irq, 0,
147			"enhanced rotary", r);
148	if (err) {
149		dev_err(&pdev->dev, "failed to request IRQ\n");
150		goto failed_free_input;
151	}
152
153	err = input_register_device(input_dev);
154	if (err) {
155		dev_err(&pdev->dev, "failed to register input device\n");
156		goto failed_free_irq;
157	}
158
159	return 0;
160
161failed_free_irq:
162	free_irq(irq, r);
163failed_free_input:
164	input_free_device(input_dev);
165failed_free_io:
166	iounmap(r->mmio_base);
167failed_free:
168	kfree(r);
169	return err;
170}
171
172static int pxa930_rotary_remove(struct platform_device *pdev)
173{
174	struct pxa930_rotary *r = platform_get_drvdata(pdev);
175
176	free_irq(platform_get_irq(pdev, 0), r);
177	input_unregister_device(r->input_dev);
178	iounmap(r->mmio_base);
179	kfree(r);
180
181	return 0;
182}
183
184static struct platform_driver pxa930_rotary_driver = {
185	.driver		= {
186		.name	= "pxa930-rotary",
187	},
188	.probe		= pxa930_rotary_probe,
189	.remove		= pxa930_rotary_remove,
190};
191module_platform_driver(pxa930_rotary_driver);
192
193MODULE_LICENSE("GPL");
194MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
195MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");